Disk drives are data storage devices that are routinely used with computers and other data processors. In a disk drive, the transducer element, commonly referred to as the head, reads and/or writes data from a spinning data-storage medium, or disk. The head is typically formed as part of an air bearing slider that is fixed to a suspension. The suspension helps to damp vibrations and keep the slider and its head steady. With reference to FIG. 1, the suspension 230 is attached to an actuator arm 210. The entire head-carrying assembly 200 is deployed to a desired radial position over the disk 100. The slider and head are not shown in FIG. 1 because they would typically be disposed on the disk-facing side of the suspension 230 near the distal end 204 of the head-carrying assembly 200. With the disk 100 spinning in the direction indicated by 120, a flow 125 is induced adjacent to the disk 100.
One of the challenges of disk-drive design is to maintain the head at a very precise location that is preferably a very small fixed distance above the disk. Variations in the height of the head from the disk increase the probability of read/write errors. An exceptional design would hold the head at a fixed height above the disk over a large range of conditions.
Modern disk-drive designs attempt to achieve this goal in part by tailoring the details of the slider. As the disk spins, the air adjacent to the disk is induced to rotate 10 substantially with the disk, as is shown in FIG. 1. Only the flow deflected by the head-carrying assembly 200 and the flow near the outside diameter of the disk 100 deviate much from the substantially solid-body rotation of the flow. The slider flies in the induced flow. The aerodynamic forces generated on the slider are balanced by the suspension to which the slider is attached. A balance between the aerodynamic forces on the slider and the restoring elastic forces imposed by the suspension is required to maintain the slider, and hence the head, at the desired fly height. However, as the head-to-disk spacing reduces further in the near future, the slider may contact with disk asperities or the disk surface itself. In such circumstances the force balance is more complex and must include the aerodynamic forces generated on the slider, the elastic forces imposed on the slider by the suspension, and the contact and frictional forces imposed on the slider by the disk contacts and friction. In addition, during data accessing, the slider is quickly moved radially by the action of the actuator. This imposes a radial inertial force to the slider and is balanced by forces generated by changing the flying attitude of the slider. To design a slider that minimizes this data accessing fly height variation is challenging.
All currently used sliders are designed so that in the induced flow, the leading portion of the slider is lifted away from the disk slightly more than the trailing portion of the slider. This type of slider has positive pitch. In a slider with positive pitch, the head is located in the trailing portion of the slider, i.e., in that portion of the slider that is closest to the disk. For disk drives with conventional flow, wiring is simplified with the location of the head in the trailing portion of the slider.